scholarly journals Application of an O-ring pinch device as a constant pressure inlet (CPI) for airborne sampling

2020 ◽  
Author(s):  
Sergej Molleker ◽  
Frank Helleis ◽  
Thomas Klimach ◽  
Oliver Appel ◽  
Hans-Christian Clemen ◽  
...  
Keyword(s):  
Constant Pressure ◽  
Inlet System ◽  
Mass Spectrometers ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Wide Range ◽  
Research Aircraft ◽  
Inner Diameter ◽  
Compact Design

Abstract. We present a novel and compact design of a constant pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, where efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hPa. The CPI device can also be used in gas phase sampling instruments in a large range of altitude and inlet pressure. The constant pressure is achieved by changing the inner diameter of a properly scaled O-ring that acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate (≈ 0.1 l/min) upstream of an aerodynamic lens constant, deviating at most by only ± 2 % from a pre-set value. In our setup a pressure sensor downstream of the O-ring controls the pinch mechanism via a feedback loop and setpoint conditions are reached within seconds. The device was implemented in a few instruments, which were successfully operated on different research aircraft covering a wide range of ambient pressures, from sea level up to about 55 hPa. Details of operation and quality of aerosol particle transmission are evaluated by laboratory experiments and in-flight data with a single particle mass spectrometer.

scholarly journals Application of an O-ring pinch device as a constant-pressure inlet (CPI) for airborne sampling

2020 ◽  
Vol 13 (7) ◽  
pp. 3651-3660
Author(s):  
Sergej Molleker ◽  
Frank Helleis ◽  
Thomas Klimach ◽  
Oliver Appel ◽  
Hans-Christian Clemen ◽  
...  
Keyword(s):  
Constant Pressure ◽  
Condensation Nucleus ◽  
Cloud Condensation Nucleus ◽  
Inlet System ◽  
Mass Spectrometers ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Wide Range ◽  
Research Aircraft ◽  
Compact Design

Abstract. We present a novel and compact design of a constant-pressure inlet (CPI) developed for use in airborne aerosol mass spectrometry. In particular, the inlet system is optimized for aerodynamic lenses commonly used in aerosol mass spectrometers, in which efficient focusing of aerosol particles into a vacuum chamber requires a precisely controlled lens pressure, typically of a few hectopascals. The CPI device can also be used in condensation particle counters (CPCs), cloud condensation nucleus counters (CCNCs), and gas-phase sampling instruments across a wide range of altitudes and inlet pressures. The constant pressure is achieved by changing the inner diameter of a properly scaled O-ring that acts as a critical orifice. The CPI control keeps air pressure and thereby mass flow rate (≈0.1 L min−1) upstream of an aerodynamic lens constant, deviating at most by only ±2 % from a preset value. In our setup, a pressure sensor downstream of the O-ring maintains control of the pinch mechanism via a feedback loop and setpoint conditions are reached within seconds. The device was implemented in a few instruments, which were successfully operated on different research aircraft covering a wide range of ambient pressures, from sea level up to about 55 hPa. Details of operation and the quality of aerosol particle transmission were evaluated by laboratory experiments and in-flight data with a single-particle mass spectrometer.

scholarly journals Aerosol pH Indicator and Organosulfate Detectability from Aerosol Mass Spectrometry Measurements

2020 ◽  
Author(s):  
Melinda K. Schueneman ◽  
Benjamin A. Nault ◽  
Pedro Campuzano-Jost ◽  
Duseong S. Jo ◽  
Douglas A. Day ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Ph Indicator ◽  
Ambient Aerosols ◽  
Mass Spectrometers ◽  
Aerosol Acidity ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Wide Range ◽  
Remote Troposphere ◽  
Total Sulfate

Abstract. Aerosol sulfate is a major component of submicron particulate matter (PM1). Sulfate can be present as inorganic (mainly ammonium sulfate, AS) or organic sulfate (OS). Although OS are thought to be a smaller fraction of total sulfate in most cases, recent literature argues that this may not be the case in more polluted environments. Aerodyne Aerosol Mass Spectrometers (AMS) measure total submicron sulfate, but it has been difficult to apportion AS vs. OS as the detected ion fragments are similar. Recently, two new methods have been proposed to quantify OS separately from AS with AMS data. We use observations collected during several airborne field campaigns covering a wide range of sources and airmass ages (spanning the continental US, marine remote troposphere, and Korea) and targeted laboratory experiments to investigate the performance and validity of the proposed OS methods. Four chemical regimes are defined to categorize the factors impacting sulfate fragmentation (Fig. shown in abstract). In polluted areas with high ammonium nitrate concentrations and in remote areas with high aerosol acidity, the decomposition and fragmentation of sulfate in the AMS is influenced by multiple complex effects, and estimation of OS does not seem possible with current methods. In regions with lower acidity (pH>0) and ammonium nitrate (fraction<0.3), the proposed OS methods might be more reliable, although application of these methods often produced nonsensical results. However, the fragmentation of ambient neutralized sulfate varies somewhat within studies, adding uncertainty, possibly due to variations in the effect of organics. Under highly acidic conditions, sulfate fragment ratios show a clear relationship with acidity (pH and ammonium balance). The measured ammonium balance (and to a lesser extent, the HySOx+/SOx+ AMS ratio) is a promising indicator for rapid estimation of aerosol pH < 0, including when gas-phase NH3 and HNO3 are not available. These results allow an improved understanding of important intensive properties of ambient aerosols.

scholarly journals Aerosol pH indicator and organosulfate detectability from aerosol mass spectrometry measurements

2021 ◽  
Vol 14 (3) ◽  
pp. 2237-2260
Author(s):  
Melinda K. Schueneman ◽  
Benjamin A. Nault ◽  
Pedro Campuzano-Jost ◽  
Duseong S. Jo ◽  
Douglas A. Day ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Ph Indicator ◽  
Ambient Aerosols ◽  
Mass Spectrometers ◽  
Aerosol Acidity ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Wide Range ◽  
Remote Troposphere ◽  
Total Sulfate

Abstract. Aerosol sulfate is a major component of submicron particulate matter (PM1). Sulfate can be present as inorganic (mainly ammonium sulfate, AS) or organosulfate (OS). Although OS is thought to be a smaller fraction of total sulfate in most cases, recent literature argues that this may not be the case in more polluted environments. Aerodyne aerosol mass spectrometers (AMSs) measure total submicron sulfate, but it has been difficult to apportion AS vs. OS as the detected ion fragments are similar. Recently, two new methods have been proposed to quantify OS separately from AS with AMS data. We use observations collected during several airborne field campaigns covering a wide range of sources and air mass ages (spanning the continental US, marine remote troposphere, and Korea) and targeted laboratory experiments to investigate the performance and validity of the proposed OS methods. Four chemical regimes are defined to categorize the factors impacting sulfate fragmentation. In polluted areas with high ammonium nitrate concentrations and in remote areas with high aerosol acidity, the decomposition and fragmentation of sulfate in the AMS is influenced by multiple complex effects, and estimation of OS does not seem possible with current methods. In regions with lower acidity (pH > 0) and ammonium nitrate (fraction of total mass < 0.3), the proposed OS methods might be more reliable, although application of these methods often produced nonsensical results. However, the fragmentation of ambient neutralized sulfate varies somewhat within studies, adding uncertainty, possibly due to variations in the effect of organics. Under highly acidic conditions (when calculated pH < 0 and ammonium balance < 0.65), sulfate fragment ratios show a clear relationship with acidity. The measured ammonium balance (and to a lesser extent, the HySOx+ / SOx+ AMS ratio) is a promising indicator of rapid estimation of aerosol pH < 0, including when gas-phase NH3 and HNO3 are not available. These results allow an improved understanding of important intensive properties of ambient aerosols.

scholarly journals Organic aerosol components observed in Northern Hemispheric datasets from Aerosol Mass Spectrometry

2010 ◽  
Vol 10 (10) ◽  
pp. 4625-4641 ◽  
Author(s):  
N. L. Ng ◽  
M. R. Canagaratna ◽  
Q. Zhang ◽  
J. L. Jimenez ◽  
J. Tian ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Organic Aerosol ◽  
Total Signal ◽  
Mass Spectral ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Wide Range ◽  
Triangular Region ◽  
Photochemical Aging ◽  
Spectral Diagnostic

Abstract. In this study we compile and present results from the factor analysis of 43 Aerosol Mass Spectrometer (AMS) datasets (27 of the datasets are reanalyzed in this work). The components from all sites, when taken together, provide a holistic overview of Northern Hemisphere organic aerosol (OA) and its evolution in the atmosphere. At most sites, the OA can be separated into oxygenated OA (OOA), hydrocarbon-like OA (HOA), and sometimes other components such as biomass burning OA (BBOA). We focus on the OOA components in this work. In many analyses, the OOA can be further deconvolved into low-volatility OOA (LV-OOA) and semi-volatile OOA (SV-OOA). Differences in the mass spectra of these components are characterized in terms of the two main ions m/z 44 (CO2+) and m/z 43 (mostly C2H3O+), which are used to develop a new mass spectral diagnostic for following the aging of OA components in the atmosphere. The LV-OOA component spectra have higher f44 (ratio of m/z 44 to total signal in the component mass spectrum) and lower f43 (ratio of m/z 43 to total signal in the component mass spectrum) than SV-OOA. A wide range of f44 and O:C ratios are observed for both LV-OOA (0.17±0.04, 0.73±0.14) and SV-OOA (0.07±0.04, 0.35±0.14) components, reflecting the fact that there is a continuum of OOA properties in ambient aerosol. The OOA components (OOA, LV-OOA, and SV-OOA) from all sites cluster within a well-defined triangular region in the f44 vs. f43 space, which can be used as a standardized means for comparing and characterizing any OOA components (laboratory or ambient) observed with the AMS. Examination of the OOA components in this triangular space indicates that OOA component spectra become increasingly similar to each other and to fulvic acid and HULIS sample spectra as f44 (a surrogate for O:C and an indicator of photochemical aging) increases. This indicates that ambient OA converges towards highly aged LV-OOA with atmospheric oxidation. The common features of the transformation between SV-OOA and LV-OOA at multiple sites potentially enable a simplified description of the oxidation of OA in the atmosphere. Comparison of laboratory SOA data with ambient OOA indicates that laboratory SOA are more similar to SV-OOA and rarely become as oxidized as ambient LV-OOA, likely due to the higher loadings employed in the experiments and/or limited oxidant exposure in most chamber experiments.

scholarly journals Organic aerosol components observed in worldwide datasets from aerosol mass spectrometry

2009 ◽  
Vol 9 (6) ◽  
pp. 27745-27789 ◽  
Author(s):  
N. L. Ng ◽  
M. R. Canagaratna ◽  
Q. Zhang ◽  
J. L. Jimenez ◽  
J. Tian ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Organic Aerosol ◽  
Aerosol Mass Spectrometer ◽  
Common Features ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Wide Range ◽  
Triangular Region ◽  
The Common ◽  
Photochemical Aging

Abstract. In this study we present results from the factor analysis of 43 aerosol mass spectrometer (AMS) datasets and provide an overview of worldwide organic aerosol (OA) components and their evolution in the atmosphere. At most sites, the OA can be separated into oxygenated OA (OOA), hydrocarbon-like OA (HOA), and sometimes other components such as biomass burning OA (BBOA). In many analyses, the OOA can be further deconvolved into low-volatility OOA (LV-OOA) and semi-volatile OOA (SV-OOA). A wide range of f44 (ratio of m/z 44 to total signal in the component mass spectrum) and O:C ratios are observed for both LV-OOA (0.17±0.04, 0.73±0.14) and SV-OOA (0.07±0.04, 0.35±0.14) components, reflecting the fact that there is a continuum of OOA properties in ambient aerosol. Differences in the mass spectra of these components are characterized in terms of the two main ions m/z 44 (CO2+) and m/z 43 (mostly C2H3O+). The LV-OOA component spectra have higher f44 and lower f43 than SV-OOA. The OOA components (OOA, LV-OOA, and SV-OOA) from all sites cluster within a well defined triangular region in the f44 vs. f43 space, which can be used as a standardized means of comparing and characterizing any OOA components (laboratory or ambient) observed with the AMS. Examination of the OOA components in this triangular space indicates that OOA component spectra become increasingly similar to each other and to fulvic acid and HULIS sample spectra as f44 (a surrogate for O:C and an indicator of photochemical aging) increases. This indicates that ambient OA converges towards highly aged LV-OOA with atmospheric oxidation. The common features of the transformation between SV-OOA and LV-OOA at multiple sites potentially enables a simplified description of the oxidation of OA in the atmosphere. Comparison of laboratory SOA data with ambient OOA indicates that laboratory SOA are more similar to SV-OOA, and rarely become as oxidized as ambient LV-OOA, likely due to the higher loadings employed in the experiments and/or limited oxidant exposure in most chamber experiments.

scholarly journals Wintertime aerosol chemical composition, volatility, and spatial variability in the greater London area

2015 ◽  
Vol 15 (16) ◽  
pp. 23173-23229
Author(s):  
L. Xu ◽  
L. R. Williams ◽  
D. E. Young ◽  
J. D. Allan ◽  
H. Coe ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Field Studies ◽  
Rural Site ◽  
Urban Site ◽  
High Temporal Resolution ◽  
Volatile Organics ◽  
Mass Spectrometers ◽  
Aerosol Mass ◽  
Rural And Urban ◽  
Wide Range

Abstract. The composition of PM1 (particulate matter with diameter less than 1 μm) in the greater London area was characterized during the Clean Air for London (ClearfLo) project in winter 2012. Two High-Resolution Time-of-Flight Aerosol Mass Spectrometers (HR-ToF-AMS) were deployed at a rural site (Detling, Kent) and an urban site (North Kensington, London). The simultaneous and high-temporal resolution measurements at the two sites provide a unique opportunity to investigate the spatial distribution of PM1. We find that the organic aerosol (OA) concentration is comparable between the rural and urban sites, but the sources of OA are distinctly different. The concentration of solid fuel OA at the urban site is about twice as high as at the rural site, due to elevated domestic heating in the urban area. While the concentrations of oxygenated OA (OOA) are well-correlated between the two sites, the OOA concentration at the rural site is almost twice that of the urban site. At the rural site, more than 70 % of the carbon in OOA is estimated to be non-fossil, which suggests that OOA is likely related to aged biomass burning considering the small amount of biogenic SOA in winter. Thus, it is possible that the biomass burning OA contributes a larger fraction of ambient OA in wintertime than what previous field studies have suggested. A suite of instruments was deployed downstream of a thermal denuder (TD) to investigate the volatility of PM1 species at the rural Detling site. After heating at 250 °C in the TD, 40 % of the residual mass is OA, indicating the presence of non-volatile organics in the aerosol. Although the OA associated with refractory black carbon (rBC, measured by a soot-particle aerosol mass spectrometer) only accounts for < 10 % of the total OA (measured by a HR-ToF-AMS) at 250 °C, the two measurements are well-correlated, suggesting that the non-volatile organics have similar sources or have undergone similar chemical processing as rBC in the atmosphere. Finally, we discuss the relationship between the OA volatility and atomic O : C and find that particles with a wide range of O : C could have similar mass fraction remaining after heating. This analysis emphasizes the importance of understanding the distribution of volatility and O : C in bulk OA.

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

A reflection of the polyethnic phenomenon in the Slovak novel of the 21 st century

2019 ◽  
pp. 462-471
Author(s):  
Lyudmila Shirokova
Keyword(s):  
Interpersonal Relations ◽  
Slovak Republic ◽  
Main Character ◽  
Jewish Family ◽  
Wide Range ◽  
Provincial Society ◽  
A Chain ◽  
Middle Generation ◽  
Artistic Quality

The historical polyethnicity of the Slovak society and the connected problems of the interrelations of cultures, ethics, interpersonal relations, are reflected in the works of modern Slovak prose. They are represented most clearly in the novels of middle generation writers P. Rankov, S. Lavrík, P. Krištúfek. They dwell upon the dramatical events of the 20 th century. They cover wide range problems, from the fruitful coexistence of various ethnic groups and their representatives to national contradictions and racial repressions. The artistic quality of the mentioned works, their composition, the way of narrating, the type of the main character, can be highly evaluated. For example, in a novel by P. Rankov the plot, in spite of its linearity, is a chain of episodes in the span of 30 years from the life of the main characters. It reflects not only their fates, but also the historical and political changes of the world they live in. The main female character of a S. Lavrík ’s novel narrates about everyday life and tragedies in the lives of the dwellers of a Slovak town in the Slovak Republic during the war. P. Krištúfek in his novel focuses on several decades from the life of a Slovak-Jewish family and dwellers of a Slovak provincial society with types and relations specific for this milieu.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

THE VALUE OF LOVE IN THE SYSTEM OF FORMATION OF THE PROFESSIONAL MATURITY OF THE EDUCATOR

2020 ◽  
Vol 1 (10(79)) ◽  
pp. 12-18
Author(s):  
G. Bubyreva
Keyword(s):  
Russian Federation ◽  
The State ◽  
Educational Process ◽  
Wide Range ◽  
The Family ◽  
The Russian Federation ◽  
The Government ◽  
The Individual ◽  
The Right

The existing legislation determines the education as "an integral and focused process of teaching and upbringing, which represents a socially important value and shall be implemented so as to meet the interests of the individual, the family, the society and the state". However, even in this part, the meaning of the notion ‘socially significant benefit is not specified and allows for a wide range of interpretation [2]. Yet the more inconcrete is the answer to the question – "who and how should determine the interests of the individual, the family and even the state?" The national doctrine of education in the Russian Federation, which determined the goals of teaching and upbringing, the ways to attain them by means of the state policy regulating the field of education, the target achievements of the development of the educational system for the period up to 2025, approved by the Decree of the Government of the Russian Federation of October 4, 2000 #751, was abrogated by the Decree of the Government of the Russian Federation of March 29, 2014 #245 [7]. The new doctrine has not been developed so far. The RAE Academician A.B. Khutorsky believes that the absence of the national doctrine of education presents a threat to national security and a violation of the right of citizens to quality education. Accordingly, the teacher has to solve the problem of achieving the harmony of interests of the individual, the family, the society and the government on their own, which, however, judging by the officially published results, is the task that exceeds the abilities of the participants of the educational process.  The particular concern about the results of the patriotic upbringing served as a basis for the legislative initiative of the RF President V. V. Putin, who introduced the project of an amendment to the Law of RF "About Education of the Russian Federation" to the State Duma in 2020, regarding the quality of patriotic upbringing [3]. Patriotism, considered by the President of RF V. V. Putin as the only possible idea to unite the nation is "THE FEELING OF LOVE OF THE MOTHERLAND" and the readiness for every sacrifice and heroic deed for the sake of the interests of your Motherland. However, the practicing educators experience shortfalls in efficient methodologies of patriotic upbringing, which should let them bring up citizens, loving their Motherland more than themselves. The article is dedicated to solution to this problem based on the Value-sense paradigm of upbringing educational dynasty of the Kurbatovs [15].

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